1. Field of the Invention
The present invention relates to an intermittent cutting transferring device configured to cut a continuum of film sheet into film sheets and intermittently transfer the film sheets to a web being continuously fed.
2. Description of the Prior Art
An intermittent cutting device is used in processes of manufacturing disposable diaper. Conventionally, the intermittent cutting device is configured to cut a continuum of film sheet, printed with patterns such as characters and figures, into the film sheets, and intermittently transfer the film sheets to a web being continuously fed.
Generally, the film sheet is configured to have lower breathability, thinner thickness and more flexibility than the web. That is, the film sheets have characteristics of low rigidity and resilience.
Such an intermittent cutting transferring device includes: an upper blade roll including blades on an outer peripheral surface; and a lower blade roll including, a stationary blade on an outer peripheral surface and a mesh suction plate over the entire outer peripheral surface (for example, see Japanese Patent Application Publication No. Hei 10-218471 (pp 4 to 6 and FIG. 3)).
The upper blade roll and the lower blade roll are configured to rotate at approximately the same peripheral velocity in directions opposite from each other. In addition, these rolls are also configured to rotate at peripheral velocities higher than the velocity in which the continuous film sheet is fed to the lower blade roll, and to rotate at peripheral velocities approximately equal to or lower than the feeding velocity of the web.
Hereinafter, steps of intermittently transferring the film sheet to the web will be described using the intermittent cutting transferring device described above.
In a first step, the intermittent cutting transferring device guides the continuum of film sheet between the blade and the stationary blade with the continuum of film sheet being sucked onto the outer peripheral surface of the lower blade roll by the suction through the mesh suction plate formed over the entire outer peripheral surface of the lower blade roll.
At this time, the continuum of film sheet slides on the outer peripheral surface of the lower blade roll to be guided between the blade and the stationary blade since the upper blade roll and the lower blade roll rotate at the peripheral velocities higher than the velocity in which the continuous film sheet is fed to the lower blade roll.
In a second step, the intermittent cutting transferring device intermittently cuts the continuum of film sheet by bringing the blade and the stationary blade into contact with each other, and thus forms a film sheet.
In a third step, the intermittent cutting transferring device guides the film sheet which is cut to the web while the film sheet which is cut is being sucked onto the outer peripheral surface of the lower blade roll by the suction through the mesh suction plate formed over the entire outer peripheral surface of the lower blade roll.
In a fourth step, the intermittent cutting transferring device transfers, to the web, the film sheet which is cut and sucked onto the outer side surface of the lower blade roll.
However, the conventional intermittent cutting transferring device described above has the following problem. That is, with the conventional intermittent cutting transferring device, a wrinkle is formed in the film sheet which is cut due to conditions such as unevenness in weight (weight per unit area) of the film sheet, contact failure of the blade and the stationary blade, and occurrence of wear in the blade.
Accordingly, the film sheet which is cut is transferred to the web with the wrinkle being formed in the film sheet. Particularly, since the film sheet which is cut has the characteristics of low rigidity and resilience, once the wrinkle is formed, the film sheet cannot be restored to its original state.